Focal Point The handwriting’s on the wall Lab researcher leaves his mark among the greats

It’s not often a researcher is remembered in the good a speaker he is.’” Balatsky said. “Of course, I presence of Albert Einstein, Enrico Fermi, J. Robert could not eat very much, as the pressure was on.” Oppenheimer, Ernest O. Lawrence, Max Planck, John Some time later, during the questions and discussion von Neumann, or other titans of science who have that followed the colloquium, several people came up left their mark on human understanding during the to Balatsky and said they enjoyed his talk very much. past century. Along with their mark on physics, these “I didn’t see anyone out in the halls laughing, so I scientists literally left their mark on a wall—the wall of guess I did okay,” he said with signature good humor. Leiden University. “Then Jan Zaanen, the organizer, comes over with Condensed-matter theorist Alexander Balatsky recently this very fancy screwdriver and leads me to the wall,” joined a handful of Los Alamos researchers who have Balatsky recalls. “They have glass over the wall, and had the privilege of signing their names alongside the glass is held in place with these special screws. He signatures of preeminent scientists who have given removed the glass, I signed the wall, and he put the colloquia at the Lorentz Institute at Leiden University glass back up. Even though it happened very quickly, in the Netherlands. one has a sense of touching something important . . . Alexander Balatsky of “It is quite an honor to speak at the Institute,” Balatsky a piece of science history.” Condensed Matter and said. “The colloquia was started by Austrian physi- —James E. Rickman Statistical Physics cist Paul Ehrenfest back in 1912, when he joined the Leiden faculty, and is very highly ranked in Europe.”

The Colloquium Ehrenfestii transformed into regular public lectures on theoretical physics in 1921. The university has drawn presentations on the leading edge of physics ever since. To commemorate each talk, presenters are invited to sign a wall at the Insti- tute. After the Institute was rebuilt in the 1960s, the original wall, which contains signatures of Einstein and similar luminaries, was retained and incorporated at the Institute’s present location. Los Alamos research- ers Kevin Bedell and Wojciech Zurek are among more recent signers.

In the tradition of colloquium founder Ehrenfest, speakers are asked to present their subject matter so anyone in attendance can easily understand it. To do so was not such an easy task for Balatsky, who was refining ideas about how certain types of crystals don’t necessarily transform from one state to another—such as from an electrically conducting state to an electri- cally resistive one—in a smooth, homogeneous fash- ion. His research into this inhomogeneity was part of a recently published paper in Nature that helped view a Mott metal-insulator transition in a vanadium crystal, something that had never been witnessed before.

“As I was preparing my talk, I attended a banquet held in the cafeteria, and I noticed that some of the faculty members were, you know, looking at me. It was kind of like they were thinking, ‘Well, we will see how

6 March 08 Currents Dixon Wolf